The invention relates to a surgical instrument, in particular, a tubular-shafted instrument, comprising two grips pivotally movable relative to one another for moving two tools movable relative to one another, and a releasable locking mechanism for securing the grips in various positions moved towards one another against movement away from one another.
Such an instrument is described in, for example, U.S. Pat. No. 4,712,545. The releasable locking mechanism comprises a slide on the grips which are pivotally movable relative to one another. When the grips are close together, the slide can be moved so far along the grips that opening is no longer possible. To be able to open the grips again, the closing movement must be continued, and the slide must subsequently be pushed back upwards again.
With such a construction, actuation of the instrument and the locking slide is only possible with both hands. In addition, there is the danger that the slide will become jammed.